JP2001174835A - Assembling apparatus for glass substrate for liquid crystal display device and method for manufacturing liquid crystal display device - Google Patents

Abstract

[PROBLEMS] To provide an alignment method, an apparatus, and a glass sheet assembling apparatus capable of accurately aligning two glass sheets without damaging a film surface or a spacer of the glass sheet. thing. SOLUTION: Temporarily bonded two glass plates 1a and 1b
Is placed on a suction plate 26, and the suction head 35 having a suction portion formed of a porous member 39 from above is used to discharge air from the porous member 39 while the upper glass plate 1 is being discharged.
a, (1b) is adsorbed, and two glass plates 1
The deviation amounts of the marks m ₁ , m ₂ ... respectively attached to a, 1b are detected, and the glass plates 1a, 1b adsorbed on the adsorption head 35 are aligned according to the detection results.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for aligning two bonded glass substrates suitable for assembling and manufacturing a liquid crystal cell and the like, and an apparatus for assembling glass substrates.

[0002]

2. Description of the Related Art Generally, a cell of a liquid crystal display panel used for a liquid crystal display usually has a spacer sandwiched between two glass substrates in order to seal liquid crystal between the two glass substrates. The two pieces of glass are overlapped with each other, temporarily attached to each other with a sealing agent applied in advance, and then the two glass pieces are accurately aligned with each other. In this state, a sandwich cell is used in which the sealing agent is cured by heating or irradiating ultraviolet rays while pressurizing the sealing agent and bonding two glass substrates together.

Since the required performance of the glass substrate differs depending on the purpose of use of the liquid crystal display, a glass substrate corresponding to each use has been developed. Roughly speaking, a soda lime glass substrate is used for a simple matrix drive LCD, and an alkali-free glass,
Borosilicate glass, quartz glass, silicon substrates and the like are used.

[0004] The thickness of a commonly used glass substrate is generally 1.1 mm. In addition, 0.
Plate thicknesses such as 7 mm, 0.5 mm and 0.4 mm have been used.

[0005] In the manufacturing process of a sandwich cell used for a liquid crystal display, one sheet (two sheets on both sides) is usually used.
A plurality of sandwich cells are formed on the glass substrate at the same time, and after the formation of the plurality, the respective sandwich cells of the glass substrates on both sides are cut and separated into individual sandwich cells.

[0006] In the aligner apparatus for two glass substrates used in the manufacturing process of these liquid crystal cells, the two glass substrates bonded and pressed in the previous process are compared with the lower glass substrate. The lower surface side is fixed by suction with a transparent suction plate, while the porous suction head is lowered to the upper surface side of the upper glass substrate to perform suction, and the position attached to each glass substrate in that state. In order to align the alignment marks, alignment is performed in the X, Y, and θ directions.

[0007]

However, in the glass substrate alignment method as described above, a spacer having a diameter of several μm is inserted between the glass substrates in order to keep the gap constant. If alignment is performed in a state where a concentrated load is applied, problems such as damaging the film surface formed inside the glass substrate or destroying the spacer occur.

Usually, in order to avoid this, the cylinder which moves the porous suction head for alignment up and down is lowered only by the weight of the porous suction head without applying air pressure at the time of lowering. Then, when contacting and aligning with the glass substrate, counter air was introduced into the vertically moving cylinder so that the porous suction head did not exert its own weight, and the pressing force against the glass substrate was almost zero.

However, when the porous suction head is lowered by its own weight, it is difficult to adjust the speed of the suction head due to the compressibility of air. Therefore, when the porous suction head comes into contact with the substrate, the impact of the descending speed affects the glass substrate, causing a spacer or the like having a low breaking strength between the glass substrates to be deformed or damaged. If alignment is performed in this state, there is a problem that the film surface inside the substrate is damaged and becomes a defective product.

The present invention has been made based on these circumstances, and is used for an alignment process of a liquid crystal cell.
An object of the present invention is to provide an alignment method, an apparatus, and a glass substrate assembling apparatus that can accurately align two glass substrates without damaging a film surface or a spacer of the glass substrate.

[0011]

According to the first aspect of the present invention, there is provided an adsorbing plate for adsorbing and holding one glass plate of two glass substrates which are temporarily joined via a spacer. A suction member having a porous member in the suction portion, and a suction head provided to be capable of ejecting or sucking air from the porous member and capable of moving back and forth with respect to the suction plate, and the two glass plates respectively. Detecting means for detecting the provided alignment mark; and aligning the glass plate by relatively moving the suction plate and the suction head based on the respective alignment marks detected by the detection means. And an alignment means for performing the following.

According to the second aspect of the present invention,
The apparatus for assembling a glass substrate for a liquid crystal display device, wherein the suction plate is an ultraviolet transmitting member, and an ultraviolet light source is provided on a side of the suction plate opposite to a suction surface of the glass substrate.

According to the third aspect of the present invention,
A process in which a glass substrate in which two glass plates are temporarily joined via a spacer is placed on a suction plate and one of the glass plates is suction-fixed, and a suction process in which a porous member is provided in a suction portion. Contacting the suction section with the other glass plate while injecting air from the porous member of the pad, and then switching from the injection of air to suction to adsorb the other glass plate; and Detecting alignment marks respectively attached to the plate and the other glass plate; detecting a deviation amount between the one glass plate and the other glass plate from the detected alignment marks; A liquid crystal display device manufacturing method for manufacturing a liquid crystal display device by an alignment method, comprising a step of performing alignment based on an amount and a step of performing final bonding with the alignment performed.

According to the fourth aspect of the present invention,
The two glass plates are temporarily bonded by an ultraviolet curing adhesive, and the ultraviolet curing adhesive is irradiated with ultraviolet rays to be cured in the main bonding step.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing an example of the configuration of a sandwich cell used in a liquid crystal display device, which is an object to be aligned by the alignment apparatus of the present invention.

[0017] That is, the glass plate 1a, successively on one side 1b, the the alkali ion prevention film 2 of SiO _2, an alignment film 3 is deposited film of SiO ₂ or the like is laminated, the ITO is in the alignment film 3 The transparent electrodes 4a, 4b, 4c,... 4n are formed. The two glass plates 1a, 1b are combined at predetermined intervals through spacers 5a, 5b,... In a direction in which the alignment films 3 face each other, and are sealed and sealed with a thermosetting or ultraviolet-curing sealing material 6. A laminated substrate (glass plate) 1 is formed. Liquid crystal 7 is filled in the sealed bonded substrate 1. An injection port 8 for injecting the liquid crystal 7 is provided on one side of the glass plate 1a, and the injection port 8 is sealed with a sealing material 6a after the liquid crystal 7 is injected.

The thickness of the liquid crystal layer in this sandwich cell can be from 1 μm or less to several hundred μm, and the area is not limited in principle.

Normally, in the steps before and after the aligner step in the manufacturing process for manufacturing a liquid crystal cell, the respective devices are arranged as shown in a plan view of the arrangement of the devices in FIG. That is, the laminating device 12 and the pressurizing device are sequentially arranged along the transport path 11 on which the substrate transport unit 10 on which the glass plates 1a and 1b are placed is moved, and along the direction in which the glass plates 1a and 1b are transported. 13, alignment device 14 and posture correction device 1
5 are provided.

The bonding device 12 is provided on both sides of the transport path 11 so as to face each other. One is for the glass plate 1a on which an array is formed, and the other is for the glass plate 1b on which a color filter is formed. Note that a dispenser (not shown) for applying a UV curing adhesive for temporary fixing is provided for the glass plate 1a on which the array is formed. On the other hand, a reversing device (not shown) for reversing the front surface and the back surface of the glass plate 1b is provided for the glass plate 1b on which the color filter is formed. The bonding device 12 is a device that forms a bonded substrate 1 after performing predetermined processing on each of the glass plates 1a and 1b, and then bonding them together and temporarily fixing them.

The pressing device 13 is a device for applying pressure using a vacuum in order to obtain a predetermined gap between the glass plates 1a and 1b of the bonded substrate 1 formed by the bonding device 12.

The alignment device 14 is provided for the bonded substrate 1
In order to accurately align the mutual positions of the two glass plates 1a and 1b that form the above, a porous suction head is provided, which is attached to the temporarily fixed glass plates 1a and 1b, which will be described later. This is a device that detects marks and performs high-precision alignment based on the results.

The posture correcting device 15 is a device for correcting the posture of the bonded substrate 1 which is constituted by a rotating mechanism for mounting and rotating the aligned bonded substrate 1.

Next, the operation of these devices will be described with reference to the schematic flow chart of the operation shown in FIG. 3. The glass plate 1a on which the array is formed and the glass plate 1b provided with the color filter are respectively Substrate transfer unit 10
Is applied to the glass plate 1a on which the alignment film is formed on the glass plate 1a on which the alignment film is formed, and a UV curable adhesive is applied in a square shape by a dispenser 16 having a predetermined width. Is done.

On the other hand, the glass plate 1b provided with the color filters is inverted by an inversion mechanism (not shown) so that the alignment film surface is on the lower surface side. Therefore, when the two glass plates 1a and 1b are overlapped, the alignment films face each other. Spacers 5a, 5b are formed on a glass plate 1a on which an array is formed.
Are dispersed, the glass plate 1b provided with the color filter is superposed on the glass plate 1b, and the glass plates 1a and 1b are bonded to each other with a UV curing adhesive. However, the lamination at this time is performed in a state in which the glass plate 1b provided with the color filter is placed on the UV curing adhesive and temporarily fixed, and the UV curing adhesive is not cured. The two glass plates 1a and 1b are not completely fixed.

The two bonded glass plates 1a,
1b forms the laminated glass plate 1 and is conveyed to the pressing device 13 by the substrate conveying unit 10 and a predetermined pressure is applied by the pressing device 13 to adjust the gap between the two glass plates 1a and 1b. . Subsequently, the bonded glass plate 1 with the adjusted gap is transported to the alignment device 14 by the substrate transport unit 10.

As shown in the schematic diagram of FIG. 4, the alignment device 14 has a hole 22 for the CCD camera 21 to pick up an image.
A transparent suction plate 26 made of quartz glass provided with suction holes (not shown) for sucking and fixing the bonded substrate 1 is fixed to a base 25 provided with holes 24 through which UV light from the UV light source 23 passes. Have been. The transparent suction plate 26 is provided with four pins (not shown) that can be moved in and out according to the size of the bonded substrate 1 on the surface on which the bonded substrate 1 is to be sucked.
Is provided.

The base 25 has a transparent suction plate 26.
A gate-shaped angle 27 is provided so as to cover the inside. A cylinder 28 is fixed to the upper part of the gate angle 27. An XYθ table 29 is fixed below the cylinder 28. Table 29 is held by a table holder 30, and this table holder 30 is movably engaged with a linear guide 31 provided inside the side pillar of the angle 27. Therefore, when the cylinder 28 operates, the XY
table 29 moves in the Z-axis direction.

A head holder 32 having a recess 33 formed in the Z-axis direction is provided below the XYθ table 29. A linear guide 34 in the Z-axis direction is formed in the concave portion 33, and a suction head 35 is movably engaged with the linear guide 34. Also, the head holder 3
A plurality of small cylinders 36a, 36b...
Are provided to hold the suction head 35.

With these configurations, the Z of the suction head 35
In the axial direction, the cylinder 28 performs a large movement integrally with the XYθ table 29, and the small movement alone of the suction head 35 independent of the movement of the XYθ table 29 is performed by the small cylinders 36a, 36b. Done.

The suction head 35 has a suction portion 37 formed of a porous member (porosity of about 40%). As shown in a plan view of the suction surface of the suction portion in FIG. Are exposed, and the other portions are covered with a porous member 39 over the suction holes 38a, 38b.

As shown in FIG. 6, a flexible hose 41 from a vacuum pump (not shown) is connected to the suction head 35, and a control unit (not shown) is provided.
The positive pressure and the negative pressure are appropriately applied by the operation of the switching valve 42 at the respective timings in accordance with the instruction from. Thereby, the injection and stop of the air and the attaching / detaching operation of the bonded substrate 1 are performed.

A recognition device having a CCD camera 21 for recognizing a mark, which will be described later, attached to the bonded substrate 1 and an image processing unit is provided below a position facing the holes 22 and 24 of the base 25. 43 and a UV light source 23 are provided.

Further, beside the transparent suction plate 26,
Substrate transport unit 1 for mounting and transporting bonded substrate 1
A transfer portion of 0 is formed. In other words, the substrate transfer unit 10 has a structure in which it can move in the horizontal direction along the transfer path 11, and an arm (not shown) on which the bonded substrate 1 is placed can also move in the Z-axis direction.

Accordingly, the bonded substrate 1 transported by the substrate transport unit 10 enters the upper portion of the transparent suction plate 26. On the other hand, with four pins (not shown) protruding on the transparent suction plate 26, the arm of the substrate transfer unit 10 on which the bonded substrate 1 is mounted moves onto the four pins, and the position of the arm moves. When descending, the bonded substrate 1
Is transferred between the four pins. After the transfer, the arm retreats and the four pins descend and enter the transparent suction plate 26, and the bonded substrate 1 is placed on the suction surface of the transparent suction plate 26 and sucked.

As shown in FIG. 7A, alignment marks m ₁ , m are provided at both ends of the center of each of the glass plates 1 a, 1 b constituting the bonded substrate 1.
₂ is attached. The marks m ₁ , m ₂ ...
As shown in (b-1) and (b-2), the upper glass plate 1
a and the lower glass plate 1b are provided at mutually symmetrical positions, and in a state where both glass plates 1a and 1b are correctly aligned, as shown in FIG. Connecting m ₁ → m ₅ → m ₂ → m ₆ results in a square. This shape may be a predetermined shape, and a square is an example.

Next, the aligner device 1 having these configurations will be described.
4 will be described with reference to the flowchart shown in FIG. Note that the reference numerals used in FIGS. 2 to 4 are used for the reference numerals of the respective units.

The two glass plates 1 a and 1 b are bonded by the bonding device 12 and the pressing device 13 to form a bonded substrate 1, which is transferred to the aligner device 14 by the substrate transfer unit 10. The aligner device 14 receives the bonded substrate 1 from the substrate transport unit 10 and places it on the transparent suction plate 26 (S1). The transparent suction plate 26 sucks and fixes the lower glass plate 1a of the bonded substrate 1 (S2).

On the other hand, the cylinder 28 for moving the suction head 35 up and down is operated to gradually lower the suction head 35 from above toward the transparent suction plate 26. Then, the suction head 35 sucks and holds the glass plate 1 b on the upper side of the bonded substrate 1 by the suction portion 37 formed of the porous member 39.

The suction head 3 of the porous member 39
When the suction head 35 is lowered by its own weight to suck the upper glass plate 1b, the air for vacuum breaking is blown out from the suction holes 38a, 38b,. By the action of the air for vacuum breaking, the suction portion 37
When the suction head 35 provided with is lowered, the impact on the bonded substrate 1 can be reduced (S3).

After the porous member 39 of the suction section 37 comes into contact with the upper glass plate 1b, counter air is supplied to the small cylinders 36a, 36b,. The self-weight is canceled, and the force in the pressing direction of the suction head 35 against the upper glass plate 1b is set to be as small as possible.

By these operations, the impact on the spacers 5a and 5b dispersed between the bonded substrates 1 can be reduced, and their deformation and breakage are prevented, and the upper glass plate 1b is sucked. (S4).

After that, the respective marks m ₁ , m ₂ , m ₁ , m ₂ , which are given to the two glass plates 1 a, 1 b by the recognition means 43 below the transparent suction plate 26 of the lower glass plate ₁ a.
It recognizes m 2 _... transparent to the (S5). In the image processing, the relative shift amounts of the respective marks m ₁ , m ₂ ... Are calculated. Incidentally, X as described above, the mark _{m 1,} m 2 _... Each of the glass plates 1a, in 1b, for example, since the + mark are marked by mark _{m 1,} m 2 _... recognition result of the mutual It is possible to calculate the amount of deviation in each of the Y and θ directions.

The XYθ table 29 as the alignment means is finely moved in accordance with the calculated relative displacement amount,
In the X, Y, and θ directions, the suction head 35 slightly moves according to the adjustment amount as needed. Thereby, the suction head 3
The upper glass plate 1b adsorbed on 5 is aligned with the lower glass plate 1a (S6).

After the alignment is completed, the UV light source 23 below the transparent suction plate 26 applies UV light to the UV sealant (applied in another process) for temporary fixing between the glass plates 1a and 1b. Curing by irradiating light (S
7).

Thereafter, the suction head 35 releases the suction holding of the upper glass plate 1b and moves up. The aligned two glass plates 1a and 1b are held by the arm of the substrate transport unit 10, are separated from the transparent suction plate 26, are raised, and are transported by the substrate transport unit 10 to the next step (S8). .

In the above-described embodiment, a transparent suction plate made of quartz glass is used for mounting the bonded substrate, but a metal suction plate such as stainless steel may be used. However, in that case, CCD on the suction plate
It is necessary to provide holes for imaging and for transmitting UV light.

As described above, according to the present invention, when the porous suction portion is formed on the glass plate and the suction head is lowered by its own weight, the porous head of the suction head is lowered. The air of the vacuum break is released. Since this air is a porous member having a porosity of about 40%, a uniform and considerable amount of air can be blown out, so that the suction head of the porous member for alignment is lowered to come into contact with the glass plate. The speed at the time can be suppressed. Thereby, the impact on the glass plate can be reduced. Also, deformation and breakage of the spacer between the glass plates can be prevented.

Further, since alignment can be performed without causing defects such as damage to the film surface inside the glass plate, extremely stable assembling of the glass plate can be performed.

[0050]

According to the present invention, when aligning two glass plates, it is possible to reduce the impact of the suction head descending to suck one of the glass plates on the glass plate. Thereby, even a spacer having a low breaking strength inserted between two glass plates can be prevented from being deformed or broken.

In addition, it is possible to prevent defects in the glass plate laminating step, and it is possible to perform accurate and stable alignment.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of an example of a liquid crystal cell.

FIG. 2 is a plan view of an arrangement of devices in processes before and after an aligner process in a manufacturing process of manufacturing a liquid crystal cell.

FIG. 3 is a schematic explanatory view of steps before and after an aligner step in a manufacturing process of manufacturing a liquid crystal cell.

FIG. 4 is a schematic structural drawing of the aligner apparatus of the present invention.

FIG. 5 is a plan view of the suction head of the present invention.

FIG. 6 is a schematic diagram of the operation of the suction head of the present invention.

FIGS. 7 (a), (b-1), (b-2) and (b-3) are explanatory views of alignment using marks according to the present invention.

FIG. 8 is a flowchart of the process of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Bonded board | substrate, 10 ... Substrate conveyance unit, 12 ... Bonding apparatus, 13 ... Pressurizing apparatus, 14 ... Alignment apparatus, 26 ... Transparent suction plate, 28 ... Cylinder, 29 ...
XYθ table, 35 ... suction heads, 36a, 36b ...
Small cylinder, 37 ... Suction part, 38a, 38b ... Suction hole,
39 ... porous member

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H088 FA01 FA30 MA20 2H089 NA01 NA38 NA44 NA51 NA60 QA12 4G061 AA18 AA33 CA02 CB02 CB03 CB04 CD02 CD12 CD14 CD22 CD23 CD24 CD25 DA26 DA36 DA61

Claims (4)

[Claims] 1. An adsorption plate for adsorbing and holding one glass plate of two glass plates temporarily bonded via a spacer, and a porous member in an adsorption section, wherein the porous member is A suction head provided for ejecting or sucking air and capable of moving back and forth with respect to the suction plate, detection means for detecting alignment marks provided on each of the two glass plates, A liquid crystal display device comprising alignment means for relatively moving the suction plate and the suction head based on the respective alignment marks detected by the means to perform alignment of the glass plate. Glass substrate assembly equipment. 2. The liquid crystal display device according to claim 1, wherein the suction plate is an ultraviolet transmitting member, and an ultraviolet light source is provided on a side of the suction plate opposite to a suction surface of the glass substrate. Glass substrate assembly equipment. 3. A step of placing a glass substrate on which two glass plates are temporarily bonded via a spacer on a suction plate to suction-fix one of the glass plates; After contacting the suction unit with the other glass plate while injecting air from the porous member of the provided suction head,
Switching the air injection to suction and sucking the other glass plate, detecting the alignment marks respectively attached to the one glass plate and the other glass plate, and detecting the alignment marks. A step of detecting a shift amount between the one glass plate and the other glass plate, a step of performing alignment based on the detected shift amount, and a step of performing final bonding in a state where the alignment is performed. A liquid crystal display device manufacturing method for manufacturing a liquid crystal display device by a characteristic alignment method. 4. The method according to claim 3, wherein the two glass plates are temporarily bonded with an ultraviolet-curing adhesive, and the ultraviolet-curing adhesive is cured by irradiating ultraviolet rays in the main bonding step. Liquid crystal display device manufacturing method.